Substrate processing device

ABSTRACT

A substrate processing apparatus includes a processing unit supplying at least one of a plurality of types of chemical liquids to a substrate and a scrubber cleaning an exhaust by bringing the exhaust in contact with a scrubbing liquid. The scrubber includes an exhaust passage that guides the exhaust, generated at the processing unit and containing the chemical liquid, toward an exhaust equipment disposed outside the substrate processing apparatus and a discharger that is able to discharge each of a plurality of types of scrubbing liquids that clean the exhaust individually inside the exhaust passage. A controller selects any one of the plurality of types of scrubbing liquids based on the type of chemical liquid contained in the exhaust and makes the selected scrubbing liquid be discharged from the discharger.

FIELD OF THE ART

The present invention relates to a substrate processing apparatusincluding a processing unit that supplies a processing liquid, such as achemical liquid, etc., to a substrate and a scrubber (gas cleaningapparatus) that cleans exhaust expelled from the processing unit.

Examples of substrates to be processed include semiconductor wafers,substrates for liquid crystal displays, substrates for plasma displays,substrates for FEDs (Field Emission Displays), substrates for opticaldisks, substrates for magnetic disks, substrates for magneto-opticaldisks, substrates for photomasks, ceramic substrates, substrates forsolar cells, etc.

BACKGROUND ART

In a manufacturing process for a semiconductor device or a liquidcrystal display, etc., an acidic or alkaline chemical liquid or anorganic chemical liquid (a liquid organic solvent) is used to process asubstrate, and exhaust containing pollutants, such as chemical liquidcomponents, etc., is thus generated. Such exhaust is removed of thepollutants by a scrubber or other apparatus that cleans the exhaust andis thereafter released to the atmosphere in a harmless state.

For example, Patent Document 1 discloses a semiconductor manufacturingapparatus, which includes a cleaning apparatus that cleans thesubstrate, a dryer that dries the cleaned substrate by using an organicsolvent and a solvent removing apparatus that removes the organicsolvent used in the drying process by the dryer and is disposed in thesemiconductor manufacturing apparatus. The organic solvent that iscontained in exhaust generated in the drying process is removed by awater mist that is injected from a vapor mist injector of the solventremoving apparatus. The exhaust that contains the pollutants is therebycleaned.

PRIOR ART DOCUMENT Patent Document

[PATENT DOCUMENT 1] Japanese Patent Application Publication No.2009-206303

SUMMARY OF THE INVENTION Problem(s) to be Solved by the Invention

A wet scrubber, which cleans exhaust using a scrubbing liquid, cleansthe exhaust by removing or neutralizing pollutants by contact betweenthe exhaust and the scrubbing liquid. To remove the pollutantsefficiently from the exhaust, a scrubbing liquid that is specialized tothe pollutants contained in the exhaust must be brought in contact withthe exhaust. For example, if an alkaline pollutant is contained in theexhaust, it is preferable to bring an acidic scrubbing liquid in contactwith the exhaust to cause a neutralization reaction.

In a manufacturing process for a semiconductor device or a liquidcrystal display, etc., a plurality of types of chemical liquids, such asan acidic chemical liquid, an alkaline chemical liquid, and an organicchemical liquid, etc., may be supplied to the same substrate. Also, evenwhen one type of chemical liquid is supplied to the substrate, the typeof chemical liquid may be changed in accordance with the contents of theprocess. The type of pollutant contained in the exhaust may thus changeduring the processing of the substrate or the type of pollutantcontained in the exhaust may change in accordance with the contents ofthe process.

With Patent Document 1, the pollutant contained in the exhaust islimited to one type (IPA (isopropyl alcohol)) and therefore there may beno problem even if the vapor mist injector can inject only one type ofscrubbing liquid (water). However, in a case where a plurality of typesof chemical liquids are supplied to the substrate or a case where thetype of chemical liquid supplied to the substrate is changed accordingto the contents of the process, it may not be possible to efficientlyclean the exhaust generated in accompaniment with the processing of thesubstrate.

Therefore an object of the present invention is to provide a substrateprocessing apparatus capable of internally cleaning exhaust generated inaccompaniment with processing of a substrate and changing the type ofscrubbing liquid, which cleans the exhaust, in accordance with the typeof pollutant contained in the exhaust.

Means for Solving the Problem

A preferred embodiment of the present invention provides a substrateprocessing apparatus including a processing unit that supplies at leastone of a plurality of types of chemical liquids to a substrate, ascrubber including an exhaust passage that guides exhaust, generated atthe processing unit and containing the chemical liquid, toward anexhaust equipment disposed outside the substrate processing apparatusand a discharger that is able to discharge each of a plurality of typesof scrubbing liquids, that clean the exhaust, individually inside theexhaust passage, the scrubber being configured to clear the exhaust bybringing the exhaust flowing through the exhaust passage in contact withthe scrubbing liquid, and a controller that selects any one of theplurality of types of scrubbing liquids based on the type of chemicalliquid contained in the exhaust and makes the selected scrubbing liquidbe discharged from the discharger. The discharger may be a sprayer thatsprays the scrubbing liquid to put the scrubbing liquid in a mist stateor a shower head that discharges the scrubbing liquid continuously froma plurality of holes.

With this arrangement, at least one of the plurality of types ofchemical liquids is supplied to the substrate. Specifically, theprocessing unit supplies two or more types of chemical liquids to thesubstrate at mutually different periods or supplies one type of chemicalliquid, selected from among the plurality of types of chemical liquids,to the substrate. The type of pollutant (chemical liquid component,etc.) contained in the exhaust may thus change during the processing ofthe substrate or the type of pollutant contained in the exhaust maychange according to the contents of the process.

The exhaust that is generated at the processing unit and contains thechemical liquid is guided toward the exterior of the substrateprocessing apparatus by the exhaust passage of the scrubber. Thedischarger of the scrubber can discharge each of the plurality of typesof scrubbing liquids individually inside the exhaust passage. Thescrubber makes the discharger discharge the scrubbing liquid inside theexhaust passage to bring the exhaust, flowing through the exhaustpassage, in contact with the scrubbing liquid. The pollutant is therebyremoved from the exhaust and the cleaned exhaust is expelled to theexhaust equipment disposed outside the substrate processing apparatus.

The type of chemical liquid contained in the exhaust changes inaccordance with the type of chemical liquid supplied to the substrate bythe processing unit. Based on the type of chemical liquid contained inthe exhaust, the controller selects the type of scrubbing liquid to bedischarged from the discharger. For example, if the type of pollutantcontained in the exhaust changes during the processing of the substrate,the controller makes a plurality of types of scrubbing liquids bedischarged from the discharger at respectively different periods. Also,if the type of pollutant contained in the exhaust changes in accordancewith the contents of the process, the controller changes the type ofscrubbing liquid according to each content of the process.

The controller thus selects any one of the plurality of types ofscrubbing liquids based on the type of chemical liquid supplied to thesubstrate and therefore even if the type of pollutant contained in theexhaust changes during the processing of the substrate or the type ofpollutant contained in the exhaust changes according to the contents ofprocess, the scrubbing liquid that is specialized to the pollutantcontained in the exhaust can be brought in contact with the exhaust. Theexhaust generated at the processing unit can thus be cleaned within thesubstrate processing apparatus and decrease a residual amount of thepollutant contained in the exhaust.

In the preferred embodiment of the present invention, the scrubberfurther includes a filter that is disposed in the exhaust passage,allows gas flowing through the exhaust passage to pass through thescrubber filter, and retains liquid internally.

With this arrangement, the scrubber filter that allows passage of gas isdisposed in the exhaust passage. When the discharger discharges thescrubbing liquid, an atmosphere that contains the scrubbing liquidattaches to the scrubber filter. The scrubbing liquid is thus retainedon an outer surface of the scrubber filter and an inner surface of thescrubber filter. The exhaust flowing through the exhaust passage in aflow-through direction toward the exterior of the substrate processingapparatus passes through voids in the interior of the scrubber filter.

In passing through the interior of the scrubber filter, the exhaust thatcontains the pollutant contacts the scrubbing liquid retained in thescrubber filter. By the scrubbing liquid being retained in the scrubberfilter, the scrubbing liquid present inside exhaust passage is increasedin surface area so that an area of contact between the exhaust and thescrubbing liquid is also increased. The pollutant is thereby removedefficiently from the exhaust.

In the preferred embodiment of the present invention, the discharger maydischarge the scrubbing liquid toward the scrubber filter.

With this arrangement, the scrubbing liquid from the discharger is blownonto the scrubber filter. The scrubbing liquid discharged from thedischarger thus hits the scrubber filter directly and the scrubbingliquid is supplied reliably to the scrubber filter. The amount ofscrubbing liquid retained by the scrubber filter is thus increased andthe exhaust is reliably brought in contact with the scrubbing liquidretained by the scrubber filter. The residual amount of the pollutantcontained in the exhaust is thereby decreased further and thecleanliness of the exhaust is improved.

In the preferred embodiment of the present invention, the scrubber mayfurther include a mist filter that is disposed in the exhaust passage ata position further downstream than the discharger and the scrubberfilter, allows gas flowing through the exhaust passage to pass throughthe mist filter, and removes a liquid component from the gas.

With this arrangement, the mist filter that allows passage of gas andremoves the liquid component from the gas is disposed in the exhaustpassage at the position further downstream than the discharger and thescrubber filter with respect to the exhaust flow-through direction. Theexhaust that is decreased in the residual amount of the pollutant bycontact with the scrubbing liquid thus passes through the mist filter.The exhaust passing through the mist filter may contain the scrubbingliquid or other liquid component. Such a liquid component is captured bythe mist filter and is removed from the exhaust. Therefore, not only thepollutant but the liquid component is also decreased in residual amountin the interior of the substrate processing apparatus.

In the preferred embodiment of the present invention, the scrubber mayfurther include a drain apparatus that expels liquid inside the exhaustpassage by making the liquid be suctioned into a drain port that opensinside the exhaust passage.

With this arrangement, a suction force of the drain apparatus istransmitted to the drain port that opens inside the exhaust passage andthe liquid inside the exhaust passage is suctioned into the drain port.The liquid inside the exhaust passage is thereby expelled. Because theexhaust that contains the chemical liquid flows into the exhaust passageand the discharger discharges the scrubbing liquid inside the exhaustpassage, liquid droplets may attach to an inner surface of the exhaustpassage or a pool of liquid may form on a bottom surface (bottom portionof the inner surface) of the exhaust passage. Therefore by the drainapparatus expelling the liquid inside the exhaust passage, the liquidcomponent is suppressed or prevented from mixing in the exhaust, anddifferent types of scrubbing liquid are suppressed or prevented fromcontacting each other inside the exhaust passage. The cleanliness insidethe exhaust passage can thus be improved and the cleanliness of theexhaust can thereby be improved further.

In the preferred embodiment of the present invention, the scrubber mayfurther include a scrubber filter that is disposed in the exhaustpassage at a position further upstream than the drain port, allows gasflowing through the exhaust passage to pass through the scrubber filter,and retains liquid internally. In this case, the drain apparatus mayinclude a drain passage passing below the scrubber filter and extendingfrom further upstream than the scrubber filter to the drain port so thatthe liquid inside the exhaust passage flows toward the drain port.

With this arrangement, the scrubber filter is disposed further upstreamthan the drain port. The drain apparatus has the drain passage passingthrough a space between the scrubber filter and the bottom surface ofthe exhaust passage and extending from further upstream than thescrubber filter to the drain port. A liquid present further upstreamthan the scrubber filter is guided toward the drain port by the drainpassage. The drain apparatus can thus collect liquid from a wider rangeof the interior of the exhaust passage and the residual amount of theliquid inside the exhaust passage can thereby be decreased.

In the preferred embodiment of the present invention, the scrubber mayfurther include a scrubber filter that is disposed in the exhaustpassage, allows gas flowing through the exhaust passage to pass throughthe scrubber filter, and retains liquid internally. In this case, thedischarger may discharge the scrubbing liquid constantly.

With this arrangement, the scrubbing liquid is discharged constantlyfrom the discharger. That is, the discharger continues to discharge thescrubbing liquid while the substrate processing apparatus is inoperation. The state in which the scrubbing liquid is retained by thescrubber filter is thus maintained reliably. The exhaust flowing throughthe exhaust passage is thus reliably brought into contact with thescrubbing liquid retained by the scrubber filter. The residual amount ofthe pollutant contained in the exhaust can thereby be decreased.Further, when the scrubber filter dries, a resistance that the scrubberfilter applies to a gas flow decreases, and therefore by maintaining thescrubber filter in a wet state, fluctuation of exhaust pressure can bedecreased. The exhaust pressure transmitted from the exhaust equipmentto the processing unit via the scrubber can thereby be stabilized.

In the preferred embodiment of the present invention, the scrubber mayfurther include a scrubber filter that is disposed in the exhaustpassage, allows gas flowing through the exhaust passage to pass throughthe scrubber filter, and retains liquid internally. In this case, thedischarger may discharge the scrubbing liquid intermittently.

With this arrangement, the scrubbing liquid is discharged intermittentlyfrom the discharger. A consumption amount of the scrubbing liquid canthus be decreased. Also, the scrubbing liquid is supplied intermittentlyto the scrubber filter and the scrubber filter can thus be preventedfrom drying completely. The exhaust can thus be cleaned and the exhaustpressure transmitted to the processing unit can be stabilized whiledecreasing the consumption amount of the scrubbing liquid.

In the case where the discharger discharges the scrubbing liquidintermittently, an interval (time from stoppage to restart of discharge)at which the discharger discharges the scrubbing liquid may be a fixedinterval determined in advance or a certain interval set based on a gaspressure in the exhaust passage. For example, the scrubber may furtherinclude an exhaust pressure sensor that detects the gas pressure in theexhaust passage and the controller may make the discharger discharge thescrubbing liquid intermittently based on a detection value of theexhaust pressure sensor.

As mentioned above, when the scrubber filter dries, the exhaustresistance of the scrubber filter decreases and the gas pressure insidethe exhaust passage thus changes. Specifically, the gas pressure furtherupstream than the scrubber filter decreases and the gas pressure furtherdownstream than the scrubber filter increases. In other words, theexhaust pressure further upstream than the scrubber filter isstrengthened (the absolute value of negative pressure increases) and thegas pressure further downstream than the scrubber filter is weakened(the absolute value of negative pressure decreases). The controller canthus maintain the state in which the scrubber filter is wettedsufficiently while decreasing the consumption amount of the scrubbingliquid by making the discharger discharge the scrubbing liquidintermittently based on the detection value of the exhaust pressuresensor.

In the preferred embodiment of the present invention, the scrubber mayfurther include a plurality of scrubber filters that allow gas flowingthrough the exhaust passage to pass through the plurality of scrubberfilters and retain liquid internally and a filter switching apparatusswitching a state of each of the plurality of scrubber filtersindividually. The filter switching apparatus may switch the state ofeach of the plurality of scrubber filters individually between a removalstate in which the gas inside exhaust passage passes through thescrubber filter and a removal stop state in which the passage of the gasthrough the scrubber filter is stopped. The controller may select anyone of the plurality of scrubber filters based on the type of chemicalliquid contained in the exhaust and causes the filter switchingapparatus to switch the states of the plurality of scrubber filters bythe filter switching apparatus such that the exhaust passes through theselected scrubber filter.

With this arrangement, any one of the plurality of scrubber filters isselected based on the type of chemical liquid supplied to the substrateby the processing unit. The filter switching apparatus switches thestates of the plurality of scrubber filters so that the exhaust that isgenerated at the processing unit and contains the chemical liquid passesthrough the selected scrubber filter. For example, if the same chemicalliquid is supplied to the substrate, the state of each individualscrubber filter is set so that the exhaust passes through the samescrubber filter. Also, when the type of chemical liquid supplied to thesubstrate is changed, the scrubber filter through which the exhaustpasses is also changed. The exhaust that is generated at the processingunit and contains the chemical liquid thus passes through a dedicatedscrubber filter that is provided according to the type of chemicalliquid. An unpredicted reaction due to mixing of a plurality of chemicalliquids can thus be prevented.

In the preferred embodiment of the present invention, the processingunit may include a gas-liquid separator that is disposed furtherupstream than the scrubber and removes liquid from the exhaust generatedat the processing unit.

With this arrangement, the gas-liquid separator disposed furtherupstream than the scrubber separates liquid from the exhaust generatedat the processing unit and removes the liquid component from theexhaust. The exhaust that has been decreased in liquid content by thegas-liquid separator is delivered to the scrubber. Therefore, even ifthe exhaust generated at the processing unit contains a chemical liquidcomponent, the exhaust is delivered to the scrubber in the state wherethe content of the chemical liquid has been decreased by the gas-liquidseparator. That is, the residual amount of the pollutant is decreased bythe gas-liquid separator and the scrubber. The cleanliness of theexhaust expelled from the substrate processing apparatus can thus beimproved further.

In the preferred embodiment of the present invention, the processingunit may include a plurality of processing units, each of which suppliesat least one of a plurality of types of chemical liquids. In this case,the exhaust passage may include a plurality of individual passagesconnected respectively to the plurality of processing units and acollection passage extending downstream from each of the plurality ofindividual passages.

With this arrangement, the plurality of individual passages of theexhaust passage are connected respectively to the plurality ofprocessing units and the collection passage of the exhaust passage isconnected to each of the plurality of individual passages. The exhaustsgenerated at the plurality of processing units are expelled from theplurality of processing units into the plurality of individual passagesrespectively. The exhausts that flowed into the plurality of individualpassages are guided via the collection passage toward the exhaustequipment disposed outside the substrate processing apparatus. Theexhaust generated at each processing unit is cleaned by contact with thescrubbing liquid in the process of flowing through the exhaust passage.The exhausts generated at the plurality of processing units can thus becleaned inside the substrate processing apparatus by the scrubber. Thereis thus no need to provide a plurality of scrubbers in the substrateprocessing apparatus in correspondence to the individual processingunits.

In the preferred embodiment of the present invention, the discharger mayinclude a plurality of dischargers disposed respectively in theplurality of individual passages.

With this arrangement, the plurality of dischargers are disposedrespectively in the plurality of individual passages. The scrubber canthus make a scrubbing liquid, of a different type from the scrubbingliquid discharged in a certain individual passage, be discharged inanother individual passage. The scrubber can thus bring the exhaust ineach individual passage in contact with the scrubbing liquid specializedto the pollutant contained in the exhaust. The scrubber can therebyefficiently remove the pollutants from the exhausts generated at theplurality of processing units.

In the preferred embodiment of the present invention, the scrubber mayfurther include a plurality of scrubber filters that are disposedrespectively in the plurality of individual passages, allow gas flowingthrough the exhaust passage to pass through the plurality of scrubberfilters, and retain liquid internally.

With this arrangement, the plurality of scrubber filters are disposedrespectively in the plurality of individual passages. The scrubber canthus bring the exhaust and the scrubbing liquid in contact reliably ineach individual passage and can increase a time of contact between theexhaust and the scrubbing liquid inside each individual passage. Thescrubber can thus efficiently remove the pollutants from the exhaustsgenerated at the plurality of processing units and further improve thecleanliness of the exhausts.

In the preferred embodiment of the present invention, the scrubber mayfurther include a plurality of mist filters that are disposedrespectively in the plurality of individual passages at positionsfurther downstream than the plurality of dischargers and the pluralityof scrubber filters, allow gas flowing through the exhaust passage topass through the plurality of mist filters, and remove a liquidcomponent from the gas.

With this arrangement, the plurality of mist filters are disposedrespectively in the plurality of individual passages. That is, adedicated mist filter is provided according to each individual passage.The scrubber can thus remove the liquid component from the exhaust ineach individual passage. The scrubber can thus reliably remove theliquid component from the exhausts generated at the plurality ofprocessing units and further improve the cleanliness of the exhausts.

In the preferred embodiment of the present invention, the discharger maybe disposed in the collection passage.

With this arrangement, the discharger is disposed in the collectionpassage. The exhausts expelled from the plurality of processing unitsflow into the collection passage through the corresponding individualpassages and contact the scrubbing liquid, discharged from thedischarger, in the collection passage. The exhausts generated at theplurality of processing units are thereby cleaned. The discharger isthus disposed in the collection passage and therefore a discharger doesnot need to be provided in each individual passage. The substrateprocessing apparatus can thus be reduced in the number of parts and canbe simplified in structure.

In the preferred embodiment of the present invention, the scrubber mayfurther include a scrubber filter that is disposed in the collectionpassage, allows gas flowing through the exhaust passage to pass throughthe scrubber filter, and retains liquid internally.

With this arrangement, the scrubber filter is disposed in the collectionpassage. The exhausts expelled from the plurality of processing unitsflow into the collection passage through the corresponding individualpassages and pass through the scrubber filter in the collection passage.The exhausts generated at the plurality of processing units are therebybrought in contact with the scrubbing liquid reliably. The scrubberfilter is thus disposed in the collection passage and therefore ascrubber filter does not need to be provided in each individual passage.The substrate processing apparatus can thus be reduced in the number ofparts and the substrate processing apparatus can be simplified instructure.

In the preferred embodiment of the present invention, the scrubber mayfurther include a mist filter that is disposed in the collection passageat a position further downstream than the discharger and the scrubberfilter, allows gas flowing through the exhaust passage to pass throughthe mist filter, and removes a liquid component from the gas.

With this arrangement, the mist filter is disposed in the collectionpassage. The exhausts expelled from the plurality of processing unitsflow into the collection passage through the corresponding individualpassages and pass through the mist filter in the collection passage. Theliquid component is thereby removed from the exhausts. The mist filteris thus disposed in the collection passage and therefore a mist filterdoes not need to be provided in each individual passage. The substrateprocessing apparatus can thus be reduced in the number of parts and thesubstrate processing apparatus can be simplified in structure.

In the preferred embodiment of the present invention, the scrubber mayfurther include a drain apparatus that expels a liquid inside theexhaust passage by making the liquid be suctioned into a drain port thatopens inside the collection passage. The drain apparatus may include aplurality of drain passages extending from the plurality of individualpassages to the collection passage and inclined with respect to ahorizontal plane such that the liquid inside the exhaust passage flowsfrom the plurality of individual passages to the collection passage.

With this arrangement, the plurality of drain passages of the drainapparatus respectively correspond to the plurality of individualpassages and each drain passage extends from the correspondingindividual passage to the collection passage. The respective drainpassages are inclined with respect to the horizontal plane anddownstream ends of the drain passages are disposed lower than theupstream ends of the drain passages so that the liquids inside theplurality of individual passages flow through the plurality of drainpassages to the collection passage by gravity. The liquids inside theplurality of individual passages are thus collected into the collectionpassage. The drain apparatus suctions the liquid inside the collectionpassage from the drain port that opens in the collection passage. Thedrain apparatus can thus collect liquid from a wider range of theinterior of the exhaust passage and the residual amount of the liquidinside the exhaust passage can thereby be decreased.

The above and yet other objects, features, and effects of the presentinvention shall be made clear by the following description of thepreferred embodiments in reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the general arrangement of a substrateprocessing apparatus according to a preferred embodiment of the presentinvention.

FIG. 2 is a schematic view of the general arrangement of a processingunit.

FIG. 3 is a process diagram of an example of processing of a substrateperformed by the processing unit.

FIG. 4 is a schematic view of the interior of a scrubber as viewed fromabove.

FIG. 5 is a schematic view of the interior of the scrubber as viewedfrom a side.

FIG. 6 is a diagram of an example of operation of the scrubber when asubstrate is being processed by the processing unit.

FIG. 7 is a schematic view of a modification example of the scrubber.

FIG. 8 is a schematic view of a modification example of the scrubber.

FIG. 9 is a schematic view of another modification example of thescrubber.

MODES FOR CARRYING OUT THE INVENTION

FIG. 1 is a schematic view of the general arrangement of a substrateprocessing apparatus 1 according to a preferred embodiment of thepresent invention. FIG. 2 is a schematic view of the general arrangementof a processing unit 2.

As shown in FIG. 1, the substrate processing apparatus 1 is a singlesubstrate processing type apparatus that processes a disk-shapedsubstrate W, such as a semiconductor wafer, etc., one by one. Thesubstrate processing apparatus 1 includes a plurality of processingunits 2 supplying processing liquids to the substrate W, a scrubber 3cleaning exhausts expelled from the respective processing units 2, abox-shaped outer wall 4 housing the plurality of processing units 2 andthe scrubber 3, and a controller 5 controlling operations of apparatusesand opening and closing of valves provided in the substrate processingapparatus 1.

As shown in FIG. 2, each processing unit 2 is a single substrateprocessing type unit that processes the substrate W one by one. Eachprocessing unit 2 has an arrangement in common to the other processingunits 2. Each processing unit 2 includes a box-shaped chamber 6 havingan internal space, a spin chuck 7 holding a single substrate W in ahorizontal attitude inside the chamber 6 and rotating the substrate Waround a vertical rotation axis A1 passing through the center of thesubstrate W, processing liquid supplying apparatuses 8 to 11, eachdischarging a processing liquid to the substrate W held by the spinchuck 7, and a cylindrical cup 12 surrounding the spin chuck 7.

As shown in FIG. 2, the chamber 6 includes a box-shaped partition wall13 housing the spin chuck 7, etc., an FFU 14 (fan filter unit) as ablower unit delivering clean air (air filtered by a filter) from anupper portion of the partition wall 13 into the interior of thepartition wall 13, and an interior exhaust duct 15 that expels a gasinside the chamber 6 from a lower portion of the partition wall 13. TheFFU 14 is disposed above the partition wall 13. The FFU 14 delivers theclean air downward into the chamber 6 from a roof of the partition wall13. The interior exhaust duct 15 is connected to a bottom portion of thecup 12 and guides the gas inside the chamber 6 toward an exhaustequipment provided in a plant in which the substrate processingapparatus 1 is installed. A down flow (downward flow) that flowsdownward inside the chamber 6 is thus formed by the FFU 14 and theindoor exhaust duct 15. The down flow is formed not only during a periodin which the substrate W is present inside the chamber 6 but in otherperiods as well.

As shown in FIG. 2, the spin chuck 7 includes a disk-shaped spin base 16holding the substrate W horizontally and a spin motor 17 rotating thesubstrate W and the spin base 16 around the rotation axis A1. The spinchuck 7 may be a clamping type chuck that holds the substrate Whorizontally by clamping the substrate W in horizontal directions or maybe a vacuum type chuck that suctions a rear surface (lower surface) ofthe substrate W that is a non-device-forming surface to hold thesubstrate W horizontally. FIG. 2 shows a case where the spin chuck 7 isa clamping type chuck that clamps the substrate W by a plurality ofchuck pins. The cup 12 surrounds the spin base 16. An upper end portionof the cup 12 that opens upward is disposed higher than the spin base16. A processing liquid, such as a chemical liquid or a rinse liquid,etc., that is expelled to a periphery of the substrate W is received bythe cup 12 and is expelled from a drain port 12 a that opens in theinterior of the cup 12.

As shown in FIG. 2, the processing liquid supplying apparatuses 8 to 11include an acidic chemical liquid nozzle that discharges an acidicchemical liquid toward the substrate W, an alkaline chemical liquidnozzle 9 that discharges an alkaline chemical liquid toward thesubstrate W, an organic chemical liquid nozzle 10 that discharges anorganic chemical liquid toward the substrate W, and a rinse liquidnozzle 11 that discharges a rinse liquid toward the substrate W. Theacidic chemical liquid nozzle 8 may be a fixed nozzle that dischargesthe processing liquid toward an upper surface central portion of thesubstrate W in a state where a discharge port is stationary or may be ascan nozzle that discharges the processing liquid while moving so that aliquid landing position of the processing liquid with respect to theupper surface of the substrate W moves between the central portion and aperipheral edge portion. The same applies to the alkaline chemicalliquid nozzle 9, the organic chemical liquid nozzle 10, and the rinseliquid nozzle 11.

As shown in FIG. 2, the processing unit 2 includes an acidic chemicalliquid piping 18 connected to the acidic chemical liquid nozzle 8 and anacidic chemical liquid valve interposed in the acidic chemical liquidpiping 18. Similarly, the processing unit 2 includes an alkalinechemical liquid piping 20 connected to the alkaline chemical liquidnozzle 9, an alkaline chemical liquid valve 21 interposed in thealkaline chemical liquid piping 20, an organic chemical liquid piping 22connected to the organic chemical liquid nozzle 10, an organic chemicalliquid valve 23 interposed in the organic chemical liquid piping 22, arinse liquid piping 24 connected to the rinse liquid nozzle 11, and arinse liquid valve 25 interposed in the rinse liquid piping 24.

When the acidic chemical liquid valve 19 is opened, the acidic chemicalliquid from an acidic chemical liquid supply source is discharged towardthe upper surface of the substrate W from the acidic chemical liquidnozzle 8. Similarly when any of the alkaline chemical liquid valve 21,the organic chemical liquid valve 23, and the rinse liquid valve 25 isopened, any of the alkaline chemical liquid, the organic chemicalliquid, and the rinse liquid is discharged toward the upper surface ofthe substrate W from any of the alkaline chemical liquid nozzle 9, theorganic chemical liquid nozzle 10, and the rinse liquid nozzle 11.

An example of the acidic chemical liquid is hydrofluoric acid and anexample of the alkaline chemical liquid is SC-1 (ammonia hydrogenperoxide mixture). An example of the organic chemical liquid is IPA(isopropyl alcohol) and an example of the rinse liquid is pure water(deionized water). The acidic chemical liquid may be an acidic chemicalliquid that contains sulfuric acid or hydrochloric acid. The alkalinechemical liquid may be an alkaline chemical liquid that contains TMAH(trimethylphenylammonium hydroxide). The organic chemical liquid is notrestricted to IPA and may be another organic chemical liquid, such asHFE (hydrofluoroether), etc. The rinse liquid is not restricted to purewater and may be any of carbonated water, electrolyzed ion water,hydrogen water, ozone water, and aqueous hydrochloric acid solution ofdilute concentration (for example, approximately 10 to 100 ppm).

As shown in FIG. 2, the processing unit 2 includes gas-liquid separator26 that separates a gas and a liquid contained in a mixed fluidgenerated inside the processing unit 2. The gas-liquid separator 26 isdisposed outside the chamber 6. The gas-liquid separator 26 includes agas-liquid separation box 27 connected to the interior exhaust duct 15,a liquid piping 28 extending from the interior of the gas-liquidseparation box 27 to the exterior of the gas-liquid separation box 27,and a gas piping 29 extending from the interior of the gas-liquidseparation box 27 to the exterior of the gas-liquid separation box 27.

As shown in FIG. 2, the gas piping 29 projects upward from a bottomsurface of the gas-liquid separation box 27. An end portion of theliquid piping 28 defines a liquid outlet 30 that opens at the gas-liquidseparation box 27 bottom surface, and an end portion of the gas piping29 defines a gas outlet 31 that opens inside the gas-liquid separationbox 27 at a height higher than the liquid outlet 30. The gas piping 29is connected to the scrubber 3 (specifically, the upstream exhaust duct32 described below). An exhaust generated inside the chamber 6 is thusexpelled to the scrubber 3 via the gas-liquid separation box 27 and thegas piping 29.

When the processing liquid is supplied to the substrate W, an exhaustthat contains vapor and mist is generated inside the chamber 6. Theexhaust (the mixed fluid of the gas and the liquid) flows through theinterior exhaust duct 15 and into the gas-liquid separation box 27. Theliquid component contained in the exhaust changes to liquid dropletsinside the gas-liquid separation box 27 and is drained from the liquidoutlet 30. The gas outlet 31 is disposed higher than the liquid outlet30 and therefore the liquid inside the gas-liquid separation box 27 isunlikely to enter the gas outlet 31. Exhaust that is decreased in aresidual amount of the liquid is thus suctioned into the gas outlet 31and expelled to the scrubber 3.

FIG. 3 is a process diagram of an example of processing of the substrateW performed by the processing unit 2. FIG. 2 and FIG. 3 shall bereferenced below.

In a state where the FFU 14 supplies clean air into the chamber 6 andthe interior exhaust duct 15 expels the gas inside the chamber 6, thatis, in the state where the down flow is formed inside the chamber 6, thecontroller 5 causes any of the acidic chemical liquid nozzle 8, thealkaline chemical liquid nozzle 9, the organic chemical liquid nozzle10, and the rinse liquid nozzle 11 to discharge the processing liquid tosupply the processing liquid to the substrate W in the rotating state.Specifically, the controller 5 controls a transfer robot (not shown) andmakes it transfer the substrate W onto the spin chuck 7. Thereafter, thecontroller 5 makes the spin chuck 7 start rotating the substrate W.

Next, an acidic chemical liquid supplying step (step S1) of supplyinghydrofluoric acid, which is an example of the acidic chemical liquid, tothe substrate W is performed. Specifically, the controller 5 opens theacidic chemical liquid valve 19 to make hydrofluoric acid be dischargedfrom the acidic chemical liquid nozzle 8 toward the upper surfacecentral portion of the substrate W while making the spin chuck 7 rotatethe substrate W. Hydrofluoric acid is thereby supplied to the uppersurface of the substrate W. When a predetermined time elapses from theopening of the acidic chemical liquid valve 19, the controller 5 closesthe acidic chemical liquid valve 19 to stop the discharge ofhydrofluoric acid.

The hydrofluoric acid, that is discharged from the acidic chemicalliquid nozzle 8, is supplied to the upper surface central portion of thesubstrate W, and spreads outward along the upper surface of thesubstrate W due to a centrifugal force generated by the rotation of thesubstrate W. A liquid film of hydrofluoric acid covering the entireupper surface of the substrate W is thereby formed on the substrate Wand hydrofluoric acid is supplied to the entire upper surface of thesubstrate W. Also, an atmosphere, that contains hydrofluoric acid and isgenerated in accompaniment with the supplying of hydrofluoric acid tothe substrate W and collision of hydrofluoric acid against an innersurface of the cup 12, is expelled from the bottom portion of the cup 12to the interior exhaust duct 15. An acidic exhaust (a gas containing theacidic chemical liquid) is thereby expelled from the interior of the cup12.

Next, a first intermediate rinse liquid supplying step (step S2) ofsupplying pure water, which is an example of the rinse liquid, to thesubstrate W is performed. Specifically, the controller 5 opens the rinseliquid valve 25 to make pure water be discharged from the rinse liquidnozzle 11 toward the upper surface central portion of the substrate Wwhile making the substrate W rotate. The liquid film of hydrofluoricacid covering the entire upper surface of the substrate W is therebyreplaced by pure water and the hydrofluoric acid on the substrate W isrinsed off by the pure water. Also, an atmosphere that contains purewater and is generated in accompaniment with the supplying of pure waterto the substrate W, etc., is expelled from the bottom portion of the cup12 to the interior exhaust duct 15. When a predetermined time elapsesfrom the opening of the rinse liquid valve 25, the controller 5 closesthe rinse liquid valve 25 to stop the discharge of pure water.

Next, an alkaline chemical liquid supplying step (step S3) of supplyingSC-1, which is an example of the alkaline chemical liquid, to thesubstrate W is performed. Specifically, the controller 5 opens thealkaline chemical liquid valve 21 to make SC-1 be discharged from thealkaline chemical liquid nozzle 9 toward the upper surface centralportion of the substrate W while making the substrate W rotate. Theliquid film of pure water covering the entire upper surface of thesubstrate W is thereby replaced by SC-1 and SC-1 is supplied to theentire upper surface of the substrate W. Also, an atmosphere thatcontains SC-1 and is generated in accompaniment with the supplying ofSC-1 to the substrate W, etc., is expelled from the bottom portion ofthe cup 12 to the interior exhaust duct 15. An alkaline exhaust (a gascontaining the alkaline chemical liquid) is thereby expelled from theinterior of the cup 12. When a predetermined time elapses from theopening of the alkaline chemical liquid valve 21, the controller 5closes the alkaline chemical liquid valve 21 to stop the discharge ofSC-1.

Next, a second intermediate rinse liquid supplying step (step S4) ofsupplying pure water, which is an example of the rinse liquid, to thesubstrate W is performed. Specifically, the controller 5 opens the rinseliquid valve 25 to make pure water be discharged from the rinse liquidnozzle 11 toward the upper surface central portion of the substrate Wwhile making the substrate W rotate. The liquid film of SC-1 coveringthe entire upper surface of the substrate W is thereby replaced by purewater and the SC-1 on the substrate W is rinsed off by the pure water.Also, an atmosphere that contains pure water and is generated inaccompaniment with the supplying of pure water to the substrate W, etc.,is expelled from the bottom portion of the cup 12 to the interiorexhaust duct 15. When a predetermined time elapses from the opening ofthe rinse liquid valve 25, the controller 5 closes the rinse liquidvalve 25 to stop the discharge of pure water.

Next, an organic chemical liquid supplying step (step S5) of supplyingIPA, which is an example of the organic chemical liquid, to thesubstrate W is performed. Specifically, the controller 5 opens theorganic chemical liquid valve 23 to make IPA be discharged from theorganic chemical liquid nozzle 10 toward the upper surface centralportion of the substrate W while making the substrate W rotate. Theliquid film of pure water covering the entire upper surface of thesubstrate W is thereby replaced by IPA and the pure water on thesubstrate W is rinsed off by IPA. Also, an atmosphere that contains IPAand is generated in accompaniment with the supplying of IPA to thesubstrate W, etc., is expelled from the bottom portion of the cup 12 tothe interior exhaust duct 15. An organic exhaust (a gas containing theorganic chemical liquid) is thereby expelled from the interior of thecup 12. When a predetermined time elapses from the opening of theorganic chemical liquid valve 23, the controller 5 closes the organicchemical liquid valve 23 to stop the discharge of IPA.

Next, a drying step (step S6) of drying the substrate W is performed.Specifically, the controller 5 makes the rotation of the substrate Waccelerate to rotate the substrate W at a high rotation speed (forexample of several thousand rpm) that is faster than the rotation speedin the acidic chemical liquid supplying step to the organic chemicalliquid supplying step. A large centrifugal force is thereby applied tothe liquid on the substrate W and the liquid attached to the substrate Wis spun off to the periphery of the substrate W. The substrate W isthereby removed of liquid and the substrate W dries. When apredetermined time elapses from the start of high-speed rotation of thesubstrate W, the controller 5 makes the rotation of the substrate W bythe spin chuck 7 stop. Thereafter, the processed substrate W is carriedout by the transfer robot from the spin chuck 7.

FIG. 4 is a schematic view of the interior of the scrubber 3 as viewedfrom above. FIG. 5 is a schematic view of the interior of the scrubber 3as viewed from a side.

As shown in FIG. 4, the scrubber 3 includes a plurality of upstreamexhaust ducts 33 connected respectively to the plurality of processingunits 2, a plurality of exhaust inflow chambers 33 connectedrespectively to the plurality of upstream exhaust ducts 32, an exhaustcollection chamber 34 connected to each of the plurality of exhaustinflow chambers 33, and a downstream exhaust duct 35 connected to theexhaust collection chamber 34. The scrubber 3 further includes aplurality of chemical liquid separators 36 that remove pollutants fromthe exhausts passing through the exhaust inflow chambers 33 and theexhaust collection chamber 34 to flow from the upstream exhaust ducts 32toward the downstream exhaust duct 35 and a plurality of mist separators37 that remove liquid components from the exhausts flowing from theplurality of chemical liquid separators 36 toward the downstream exhaustduct 35.

As shown in FIG. 4, the scrubber 3 includes an exhaust cleaning box 38connected to the plurality of upstream exhaust ducts 32. The exhaustcleaning box 38 includes a box-shaped housing 39 having an internalspace and a partition wall 40 partitioning the interior of the housing39. The exhaust inflow chambers 33 and the exhaust collection chamber 34are provided in the interior of the housing 39 and are defined by thehousing 39 and the partition wall 40. The exhaust inflow chambers 33 andthe exhaust collection chamber 34 are thus defined by a member in common(the exhaust cleaning box 38).

As shown in FIG. 4, the scrubber 3 includes an exhaust passage 41 thatguides the exhausts, generated at the plurality of processing units 2,toward the exhaust equipment disposed outside the substrate processingapparatus 1. The exhaust passage 41 includes a plurality of individualpassages 42 connected respectively to the plurality of processing units2 and a collection passage 43 connected to each of the plurality ofindividual passages 42. Each individual passage 42 extends from thecorresponding processing unit 2 to the collection passage 43. Theindividual passage 42 is defined by the upstream exhaust duct 32, thehousing 39, and the partition wall 40 and the collection passage 43 isdefined by the housing 39 and the downstream exhaust duct 35. Theexhausts generated at the plurality of processing units 2 flow from theplurality of individual passages 42 into the collection passage 43 andare guided to the downstream side (exhaust equipment side) by thecollection passage 43.

Each individual passage 42 is a passage through which an exhaust priorto being filtered by a mist filter 48 to be described below flows andthe collection passage 43 is a passage through which the exhaustfiltered by the mist filter passes. That is, the individual passage 42and the collection passage 43 are functionally divided in terms ofwhether or not the exhaust passing through the passage has been filteredby the mist filter 48. On the other hand, the exhaust inflow chamber 33and the exhaust collection chamber 34 are structurally divided in termsof being or not being partitioned by the partition wall 40. That is, theexhaust inflow chamber is a portion in the exhaust cleaning box 38 thatis partitioned by the partition wall 40 and the exhaust collectionchamber 34 is a portion in the exhaust cleaning box 38 that is notpartitioned by the partition wall 40.

As shown in FIG. 1, the plurality of upstream exhaust ducts 32 areconnected respectively to the plurality of gas pipings 29 providedrespectively in the plurality of processing units 2. As shown in FIG. 4,each upstream exhaust duct 32 extends from the corresponding processingunit 2 to the corresponding exhaust collection chamber 34. An upstreamend of the upstream exhaust duct 32 is connected to the gas piping 29and a downstream end portion of the upstream exhaust duct 32 isconnected to a gas inlet 44 that opens at an inner surface of theexhaust collection chamber 34. The plurality of exhaust inflow chambers33 are thus connected respectively to the plurality of processing units2 via the plurality of upstream exhaust ducts 32.

As shown in FIG. 4, the respective exhaust inflow chambers 33 extend ina flow-through direction D1 of the exhaust flowing from the processingunits 2 toward the exhaust equipment. The plurality of exhaust inflowchambers 33 are parallel to each other. The exhaust that flows into anexhaust inflow chamber 33 is guided in the flow-through direction D1 bythe exhaust inflow chamber 33. A flow passage area (cross-sectional areaorthogonal to the flow-through direction D1) of the exhaust inflowchamber 33 is greater than a flow passage area of the upstream exhaustduct 32. An upstream end portion of each exhaust inflow chamber 33 isconnected to the corresponding upstream exhaust duct 33 and a downstreamend portion of each exhaust inflow chamber 33 is connected to theexhaust collection chamber 34.

As shown in FIG. 4, the exhaust collection chamber 34 is disposedfurther downstream than all exhaust inflow chambers 33. A flow passagearea of the exhaust collection chamber 34 is greater than the flowpassage area of the exhaust inflow chamber 33 and greater than a flowpassage area of the downstream exhaust duct 35. As shown in FIG. 5, anupstream end portion of the downstream exhaust duct 35 is connected toan opening portion that opens at a bottom surface (bottom portion of theinner surface) of the exhaust collection chamber 34. An upstream endportion of the downstream exhaust duct 35 projects upward from thebottom surface of the exhaust collection chamber 34 and defines anexhaust outlet 45 that opens at a height higher than the bottom surfaceof the exhaust collection chamber 34. The exhaust collection chamber 34is connected via the downstream exhaust duct 35 to the exhaustequipment. A suction force of the exhaust equipment is thus transmittedto the exhaust collection chamber 34 via the downstream exhaust duct 35.The suction force of the exhaust equipment is thus transmitted to allprocessing units 2 via the scrubber 3.

As shown in FIG. 4, each exhaust inflow chamber 33 houses the chemicalliquid separator 36 and the mist separator 37. Further, each exhaustinflow chamber 33 houses two sprayers 54 described below. The chemicalliquid separator 36 is disposed further upstream in the exhaustflow-through direction D1 than the mist separator 37. The two sprayers54 are disposed respectively upstream and downstream the chemical liquidseparator 36.

As shown in FIG. 4, the chemical liquid separator 36 partitions theinternal space of the exhaust inflow chamber into two spaces aligned inthe exhaust flow-through direction D1. The space inside the exhaustinflow chamber 33 between the gas inlet 44 and the chemical liquidseparator 36 is an upstream cleaning space, and the space inside theexhaust inflow chamber 33 between the chemical liquid separator 36 andthe mist separator 37 is a downstream cleaning space. The two sprayers54 are disposed respectively in the upstream cleaning space and thedownstream cleaning space. The mist separator 37 is disposed inside adownstream end portion of the exhaust inflow chamber 33 and partitionsthe exhaust inflow chamber 33 and the exhaust collection chamber 34.That is, the space further downstream than the mist separator 37 is theinterior (exhaust collection space) of the exhaust collection chamber34.

As shown in FIG. 4, the chemical liquid separator 36 includes amesh-shaped scrubber filter 46 that allows passage of gas and liquid inthe exhaust flow-through direction D1 and a filter case 47 holding thescrubber filter 46. The mist separator 37 includes a mesh-shaped mistfilter 48 that allows passage of gas in the exhaust flow-throughdirection D1 and a mist filter case 49 holding the mist filter 48. Thescrubber filter 46 is housed inside the filter case 47 and the mistfilter 48 is housed inside the mist filter case 49. The filter case 47and the mist filter case 49 are mounted to the exhaust cleaning box 38.The chemical liquid separator 36 and the mist separator 37 are thus heldby the exhaust cleaning box 38.

As shown in FIG. 4, the filter case 47 includes a plurality of openingsconnecting the interior of the filter case 47 and the exterior of thefilter case 47. The plurality of openings provided in the filter case 47include an upstream opening 50 disposed further upstream than thescrubber filter 46, a downstream opening 51 disposed further downstreamthan the scrubber filter 46, and a lower opening 52 (see FIG. 5)disposed below the scrubber filter 46. The scrubber filter 46 is exposedfrom the plurality of openings provided in the filter case 47. As shownin FIG. 5, a lower surface of the filter case 47 faces a bottom surface(bottom portion of the inner surface) of the exhaust cleaning box 38across an interval in a vertical direction. The vertical directioninterval between the lower surface of the filter case 47 and a bottomsurface of the exhaust cleaning box 38 is sufficiently smaller than aheight of the chemical liquid separator 36.

In the same manner as in the filter case 47, the mist filter case 49includes a plurality of openings connecting the interior of the mistfilter case 49 and the exterior of the mist filter case 49. Theplurality of openings provided in the mist filter case 49 include anupstream opening 50 disposed further upstream than the mist filter 48, adownstream opening 51 disposed further downstream than the mist filter48, and a lower opening 52 disposed below the mist filter 48. The mistfilter 48 is exposed from the plurality of openings provided in the mistfilter case 49. A lower surface of the mist filter case 49 faces thebottom surface of the exhaust cleaning box 38 across an interval in thevertical direction. The vertical direction interval between the lowersurface of the mist filter case 48 and the bottom surface of the exhaustcleaning box 38 is sufficiently smaller than a height of the mistseparator 37.

The scrubber filter 46 has a height equal to that of the mist filter 48and has a width equal to that of the mist filter 48. As shown in FIG. 4,the scrubber filter 46 is longer in the exhaust flow-through directionD1 than the mist filter 48. The scrubber filter 46 is a coarser filterthan the mist filter 48. The scrubber filter 46 thus allows passage ofgas and liquid. Also, the mist filter 48 is a finer filter than thescrubber filter 46, allows passage of gas only, and is capable ofselectively removing just liquid.

The exhaust that is suctioned into the exhaust inflow chamber 33 fromthe processing unit 2 by the suction force of the exhaust equipment issupplied to the scrubber filter 46 inside the filter case 47 through theupstream opening 50 of the filter case 47. The exhaust that has passedthrough the scrubber filter 46 moves from the interior of the filtercase 47 to the exterior of the filter case 47 through the downstreamopening 51 of the scrubber filter 46. Thereafter, the exhaust that haspassed through the chemical liquid separator 36 is supplied to the mistfilter 48 inside the mist filter case 49 through the upstream opening 50of the mist filter case 49. The exhaust that has passed through the mistfilter 48 then moves from the interior of the mist filter case 49 to theexterior of the mist filter case 49 through the downstream opening 51 ofthe mist filter 48. Thereafter, the exhaust that has passed through themist separator 37 is guided to the exhaust equipment via the downstreamexhaust duct 35.

As shown in FIG. 4, the scrubber 3 includes a spraying apparatus 53 thatsprays a scrubbing liquid that cleans the exhaust inside the scrubber 3.The spraying apparatus 53 sprays an acidic, alkaline, or neutralscrubbing liquid inside the scrubber 3 in accordance with the type ofchemical liquid supplied to the substrate W in the processing unit 2.FIG. 4 shows an arrangement example where each of an acidic scrubbingliquid and a neutral scrubbing liquid is sprayed individually inside thescrubber 3. An example of the acidic scrubbing liquid is dilute sulfuricacid and an example of the neutral scrubbing liquid is water (industrialwater). The acidic scrubbing liquid may be an acidic liquid other thandilute sulfuric acid and the neutral scrubbing liquid may be a neutralliquid having water as the main component. As an alkaline scrubbingliquid, a dilute ammonia aqueous solution, etc., may be used.

The spraying apparatus 53 is an apparatus that brings the exhaust,expelled from the processing unit 2, in contact with the mist of thescrubbing liquid to make the mist of the scrubbing liquid capturepollutants contained in the exhaust. As shown in FIG. 4, the sprayingapparatus 53 includes the plurality of sprayers 54 that spray thescrubbing liquid inside the scrubber 3 and a scrubbing liquid supplyingapparatus 55 that supplies the scrubbing liquids to the respectivesprayers 54. The plurality of sprayers 54 are disposed in the interiorof the exhaust cleaning box 38. The plurality of sprayers 54 include theplurality of pairs of sprayers 54 disposed respectively in the pluralityof exhaust inflow chambers 33. The sprayers 54 of each pair are disposedrespectively upstream and downstream the chemical liquid separator 36.

As shown in FIG. 4 and FIG. 5, each sprayer 54 includes a spray column56 of circular columnar shape disposed inside the exhaust inflow chamber33 and a plurality of spray nozzles 57 projecting outward from an outerperipheral surface of the spray column 56. The spray column 56 extendsin the vertical direction. The plurality of spray nozzles 57 aredisposed respectively at different heights and are disposed at twopositions separated in a circumferential direction of the spray column56 in a plan view. A spray port of each spray nozzle 57 faces thechemical liquid separator 36.

Each spray nozzle 57 is connected to a scrubbing liquid flow passageprovided in the interior of the spray column 56. The scrubbing liquidsupplied from the scrubbing liquid supplying apparatus 55 and throughthe spray column 56 is sprayed in conical form by each spray nozzle 57.A mist of the scrubbing liquid is thereby made to drift in the interior(the upstream cleaning space and the downstream cleaning space) of theexhaust inflow chamber 33 and the exhaust expelled from the processingunit 2 is brought in contact with the mist of the scrubbing liquid.Further, each spray nozzle 57 sprays the scrubbing liquid towardchemical liquid separator 36 and therefore liquid droplets of thescrubbing liquid are supplied to the outer surface and the inner surfaceof the scrubber filter 46 and become retained in the interior of thescrubber filter 46. The exhaust passing through the scrubber filter 46thus also contacts the scrubbing liquid retained by the scrubber filter46.

As shown in FIG. 4, the scrubbing liquid supplying apparatus 55 includesa plurality of scrubbing liquid supplying units 58 connectedrespectively to the plurality of pairs of sprayers 54. The plurality ofscrubbing liquid supplying units 58 correspond respectively to theplurality of exhaust inflow chambers 33. Each scrubbing liquid supplyingunit 58 supplies the scrubbing liquid to the corresponding pair ofsprayers 54. Each scrubbing liquid supplying unit 58 can supply thescrubbing liquid to the corresponding pair of sprayers 54 regardless ofthe operation circumstances of the other scrubbing liquid supplyingunits 58. Each scrubbing liquid supplying unit 58 is thus independent ofthe other scrubbing liquid supplying units 58.

As shown in FIG. 4, each scrubbing liquid supplying unit 58 includes anupstream scrubbing liquid piping 59 connected to the sprayer 54 at theupstream side, a downstream scrubbing liquid piping 60 connected to thesprayer 54 at the downstream side, a collection piping 61 connected tothe upstream scrubbing liquid piping 59 and the downstream scrubbingliquid piping 60, and an in-line mixer 62 interposed in the collectionpiping 61. Although unillustrated, the in-line mixer 62 includes apiping interposed in the collection piping 61 and a stirring fin that isdisposed inside the piping and is twisted around an axis extending in anaxial direction of the piping. A mixed fluid supplied into the in-linemixer 62 (into the piping) is mixed uniformly while flowing spirallyalong the stirring fin.

As shown in FIG. 4, each scrubbing liquid supplying unit 58 includes anacidic liquid piping 63 connected to the collection piping 61, an acidicliquid valve 64 interposed in the acidic liquid piping 63, and a firstflow control valve 65 interposed in the acidic liquid piping 63. Eachscrubbing liquid supplying unit 58 further includes a neutral liquidpiping 66 connected to the collection piping 61, a neutral liquid valve67 interposed in the neutral liquid piping 66, and a second flow controlvalve 68 interposed in the neutral liquid piping 66. An example of anacidic liquid is concentrated sulfuric acid, and an example of a neutralliquid is water. The acidic scrubbing liquid mentioned above is adiluted solution obtained by diluting the acidic liquid with the neutralliquid.

When the acidic liquid valve 64 is opened, the acidic liquid inside theacidic liquid piping 63 flows into the collection piping 61 at a flowrate corresponding to an opening degree of the first flow control valve65. Similarly, when the neutral liquid valve 67 is opened, the waterinside the neutral liquid piping 66 flows into the collection piping 61at a flow rate corresponding to an opening degree of the second flowcontrol valve 68. Therefore, in a state where the acidic liquid valve 64is closed and the neutral liquid valve 67 is opened, the water suppliedfrom the neutral liquid piping 66 to the collection piping 61 flows atequal flow rates into the upstream scrubbing liquid piping 59 and thedownstream scrubbing liquid piping 60 and is supplied at equal flowrates to the pair of sprayers 54. The water as the neutral scrubbingliquid is thereby sprayed at equal flow rates from the pair of sprayers54.

Also, in a state where both the acidic liquid valve 64 and the neutralliquid valve 67 are opened, water and concentrated sulfuric acid aresupplied to the collection piping 61 at a predetermined ratio (forexample, 100 to 1000 (water):1 (concentrated sulfuric acid)). The waterand the concentrated sulfuric acid are then mixed inside the piping bythe in-line mixer 62. The water and the concentrated sulfuric acid arethereby stirred to form dilute sulfuric acid. The dilute sulfuric acidthus flows at equal flow rates into the upstream scrubbing liquid piping59 and the downstream scrubbing liquid piping 60 and is supplied atequal flow rates to the pair of sprayers 54. The dilute sulfuric acid asthe acidic scrubbing liquid is thereby sprayed at equal flow rates fromthe pair of sprayers 54.

When the sprayers 54 spray the scrubbing liquid, the mist of thescrubbing liquid disperses in the upstream cleaning space and thedownstream cleaning space and the liquid droplets of the scrubbingliquid become retained in the interior of the scrubber filter 46. Due tocontact with the scrubbing liquid mist drifting in the upstream cleaningspace, the exhaust that flows into the upstream cleaning space from theupstream exhaust duct 32 becomes decreased in the residual amount of thechemical liquid component. Further, the exhaust passing through thescrubber filter 46 becomes decreased in the residual amount of thechemical liquid component due to contact with the scrubbing liquidinside the scrubber filter 46. The exhaust that flows into thedownstream cleaning space becomes decreased in the residual amount ofthe chemical liquid component due to contact with the scrubbing liquidmist drifting in the downstream cleaning space. The exhaust expelledfrom the processing unit 2 is thereby cleaned.

Also, when the sprayers 54 spray the acidic scrubbing liquid, such asthe dilute sulfuric acid, etc., the mist of the acidic scrubbing liquiddisperses in the upstream cleaning space and the downstream cleaningspace, and the liquid droplets of the acidic scrubbing liquid becomeretained in the interior of the scrubber filter 46. When an alkalineexhaust expelled from the processing unit 2 flows into the upstreamcleaning space in this state, the residual amount of the chemical liquidcomponent in the alkaline exhaust is decreased by neutralization.Similarly, the residual amount of the chemical liquid component isdecreased further by the neutralization reaction inside the scrubberfilter 46 and the neutralization reaction in the downstream cleaningspace. The alkaline chemical liquid contained in the alkaline exhaust isthereby removed and the exhaust expelled from the processing unit 2 iscleaned.

A gas (the exhaust after cleaning; hereinafter referred to as the“cleaned gas”) that is decreased in the chemical liquid component due tocontact with the scrubbing liquid mist or the scrubbing liquid dropletspasses through the mist filter 48 of the mist separator 37. The cleanedgas may contain a liquid component, such as the scrubbing liquid, etc.The mist filter 48 is a finer filter than the scrubber filter 46 andtherefore allows passage of just gas and is capable of selectivelyremoving just liquid. Therefore, even if a liquid component is containedin the cleaned gas, the liquid component in the cleaned gas can beremoved by the mist filter 48 by passage through the mist filter 48. Acleaned gas (final cleaned gas) that is removed of the liquid component,such as the scrubbing liquid, etc., is thereby guided via the downstreamexhaust duct 35 to the exhaust equipment disposed outside the substrateprocessing apparatus 1.

As shown in FIG. 5, the scrubber 3 includes a drain apparatus 69 thatexpels liquid from inside the exhaust passage 41. The drain apparatus 69includes a drain piping 70 connected to the exhaust passage 41 and adrain passage 71 guiding the liquid inside the exhaust passage 41 towardthe drain piping 70. As shown in FIG. 4, the drain apparatus 69 furtherincludes a suction apparatus 72 that suctions fluid inside the drainpiping 70. The suction apparatus 72 includes an aspirator 74 thatsuctions the fluid inside the drain piping 70. The suction apparatus 72may include a pump that suctions the fluid inside drain piping 70instead of the aspirator 74 or may include both the aspirator 74 and thepump.

As shown in FIG. 5, the drain piping 70 extends downward from the bottomsurface of the exhaust collection chamber 34. An upstream end portion ofthe drain piping 70 is connected to a drain port 73 that opens at thebottom surface (bottom portion of the inner surface) of the exhaustcollection chamber 34. As shown in FIG. 4, a downstream end portion ofthe drain piping 70 is connected to the suction apparatus 72. The drainport 73 is disposed at a periphery of the exhaust outlet 45 in a planview. An opening area of the drain port 73 is smaller than an openingarea of the exhaust outlet 45. As shown in FIG. 5, the upstream endportion of the downstream exhaust duct 35 projects upward from thebottom surface of the exhaust collection chamber 34 and opens at aposition higher than the drain port 73. The exhaust outlet 45 is thusdisposed higher than the drain port 73. Liquid on the bottom surface ofthe exhaust collection chamber 34 is thus prevented from entering intothe exhaust outlet 45 by the upstream end portion of the downstreamexhaust duct 35.

As shown in FIG. 5, the drain passage 71 is constituted by the bottomsurface (bottom portion of the inner surface) of the exhaust cleaningbox 38. The drain passage 71 extends from a space (the upstream cleaningspace) further upstream than the chemical liquid separator 36 to theinterior (the exhaust collection space) of the exhaust collectionchamber 34. The drain passage 71 includes a gap between a lower surfaceof the chemical liquid separator 36 and the bottom surface of theexhaust cleaning box 38. Similarly, the drain passage 71 includes a gapbetween the lower surface of the mist separator 37 and the bottomsurface of the exhaust cleaning box 38. The drain passage 71 is inclinedwith respect to a horizontal plane (alternate long and two short dashesline in FIG. 5) so as to be positioned lower as the drain port 73 isapproached. The liquid on the bottom surface of the exhaust cleaning box38 thus flows by gravity along the bottom surface of the exhaustcleaning box 38 toward the drain port 73. The liquid inside the exhaustinflow chamber 33 and the exhaust collection chamber 34 is therebyguided toward the drain piping 70.

Liquid on the bottom surface of the exhaust inflow chamber 33 is guidedtoward the drain piping 70 by the drain passage 71. Also, liquid insidethe scrubber filter 46 drops downward from the scrubber filter 46. Asshown in FIG. 5, the liquid that drops downward from the scrubber filter46 passes through the lower opening 52 connecting the interior of thefilter case 47 and the space below the filter case 47 and lands on thebottom surface of the exhaust inflow chamber 33. Similarly, liquidinside the mist filter 48 passes through the lower opening 52 connectingthe interior of the mist filter case 49 and the space below the mistfilter case 49 and lands on the bottom surface of the exhaust inflowchamber 33. The liquid that has dropped onto the bottom surface of theexhaust inflow chamber 33 is guided toward the drain piping 70 by thedrain passage 71 and is expelled to the drain port 73.

As shown in FIG. 4, the suction apparatus 72 includes the aspirator 74that suctions the fluid inside the drain piping 70, a liquid supplyingpiping 75 supplying liquid into the aspirator 74, a liquid expellingpiping 76 through which the liquid inside the aspirator 74 is expelled,and a drain valve 77 interposed in the liquid supplying piping 75. Theliquid supplying piping 75 is connected to an inflow port of theaspirator 74 into which the liquid flows, and the liquid expellingpiping 76 is connected to an outflow port of the aspirator 74 from whichthe liquid flows out. The drain piping 70 is connected to a suction portof the aspirator 74 that suctions the drain liquid. The liquid supplyingpiping 75 is connected to a liquid supply source in common to thespraying apparatus 53.

In a state where the drain valve 77 interposed in the liquid supplyingpiping 75 is opened, water, which is an example of the liquid, flowsfrom the liquid supplying piping 75 to the liquid expelling piping 76through a T-shaped flow passage (not shown) provided in the interior ofthe aspirator 74. In this process, a suction force that suctions thefluid inside the drain piping 70 is generated and the drain liquidinside the drain piping 70 flows through the interior of the aspirator74 and into the liquid expelling piping 76. The drain liquid inside thedrain piping 70 is thereby expelled forcibly. Liquid on the bottomsurface of the exhaust cleaning box 38 is thus expelled rapidly andreliably into the drain piping 70. Retention of liquid on the bottomsurface of the exhaust cleaning box 38 can thus be suppressed orprevented.

As shown in FIG. 4, the scrubber 3 includes a plurality of upstreamexhaust pressure sensors 78 detecting an exhaust pressure furtherupstream than the chemical liquid separator 36 and a downstream exhaustpressure sensor 79 detecting the exhaust pressure further downstreamthan the chemical liquid separator 36. The plurality of the upstreamexhaust pressure sensors 78 correspond respectively to the plurality ofprocessing units 2, and the downstream exhaust pressure sensor 79corresponds to all processing units 2. The downstream exhaust pressuresensor 79 is connected to the exhaust collection chamber 34. Theupstream exhaust pressure sensor 78 is connected to the upstream exhaustduct 32 or the exhaust inflow chamber 33. FIG. 4 shows an example whereall upstream exhaust pressure sensors 78 are connected to the upstreamexhaust duct 32.

Detection values of the upstream exhaust pressure sensors 78 and thedownstream exhaust pressure sensor 79 are input into the controller 5.When the scrubber filter 46 of the chemical liquid separator 36 iswetted sufficiently with the scrubbing liquid, a pressure loss at thescrubber filter 46 is large and a difference between the detectionvalues of the upstream exhaust pressure sensor 78 and the downstreamexhaust pressure sensor 79 is large. Therefore based on the detectionvalues of the upstream exhaust pressure sensor 78 and the downstreamexhaust pressure sensor 79, the controller 5 can judge whether or not asufficient amount of the scrubbing liquid is retained by the scrubberfilter 46.

FIG. 6 is a diagram of an example of operation of the scrubber 3 whenthe substrate W is being processed by the processing unit 2.

As mentioned above, at the processing unit 2, the acidic chemical liquidsupplying step (step S1), the first intermediate rinse liquid supplyingstep (step S2), the alkaline chemical liquid supplying step (step S3),the second intermediate rinse liquid supplying step (step S4), theorganic chemical liquid supplying step (step S5), and the drying step(step S6) are performed in that order. Each of the acidic chemicalliquid valve 19, the alkaline chemical liquid valve 21, the organicchemical liquid valve 23, and the rinse liquid valve 25 is opened andclosed in accordance with the step being performed at the processingunit 2.

As shown in FIG. 6, for example, in the acidic chemical liquid supplyingstep (step S1), the acidic chemical liquid valve 19 is opened, and thealkaline chemical liquid valve 21, the organic chemical liquid valve 23,and the rinse liquid valve 25 are closed. By the changing of the valvethat is opened, the acidic chemical liquid supplying step, the firstintermediate rinse liquid supplying step, the alkaline chemical liquidsupplying step, the second intermediate rinse liquid supplying step, andthe organic chemical liquid supplying step are performed successively.

On the other hand, as shown in FIG. 6, at the scrubber 3, regardless ofthe step being performed at the processing unit 2, that is, during theperiod from the acidic chemical liquid supplying step to the dryingstep, the neutral liquid valve 67 corresponding to this processing unit2 is open and water is discharged (see upper stage of scrubber valveoperations). Similarly, the drain valve 77 is open during the periodfrom the acidic chemical liquid supplying step to the drying step (seelower stage of the scrubber valve operations). The neutral liquid valve67 and the drain valve 77 are thus constantly open. Therefore thesprayers 54 corresponding to the present processing unit 2 constantlyspray water as the scrubbing liquid and the drain apparatus 69constantly expels the liquid on the bottom surface of the exhaustcleaning box 38.

Although not shown, the neutral liquid valve 67 is also open during aperiod in which processing of the substrate W at the processing unit 2is not being performed. The sprayers 54 spray the scrubbing liquidtoward the chemical liquid separator 36 and while the spraying of wateris being performed, the scrubber filter 46 of the chemical liquidseparator 36 is maintained in a state of being wetted with water. Thedifference between the exhaust pressure further upstream than thechemical liquid separator 36 and the exhaust pressure further downstreamthan the chemical liquid separator 36 is thus maintained fixed.Similarly, all of the neutral liquid valves 67 corresponding to theother processing units 2 are also constantly open. The exhaust pressureapplied to each processing unit 2 is thus maintained fixed.

When the acidic chemical liquid supplying step is started at a certainprocessing unit 2, that is, when the supplying of the acidic chemicalliquid to the substrate W is started, the acidic exhaust flows into theexhaust inflow chamber 33 corresponding to this processing unit 2.Similarly, when the alkaline chemical liquid supplying step is startedat a certain processing unit 2, the alkaline exhaust flows into theexhaust inflow chamber 33 corresponding to this processing unit 2.Similarly, when the organic chemical liquid supplying step is started ata certain processing unit 2, the organic exhaust flows into the exhaustinflow chamber 33 corresponding to this processing unit 2. At theprocessing unit 2, the acidic chemical liquid (hydrofluoric acid), thealkaline chemical liquid (SC-1), and the organic chemical liquid (IPA)are supplied to the substrate W and therefore the acidic exhaust, thealkaline exhaust, and the organic exhaust flow respectively at differentperiods into the exhaust inflow chamber 33.

As shown in FIG. 6, during the period in which the alkaline chemicalliquid supplying step (step S3) is being performed at the processingunit 2, the acidic liquid valve 64 of the scrubber 3 is open and dilutesulfuric acid is discharged (see middle stage of the scrubber valveoperations). In opening and closing the acidic liquid valve 64 of thescrubber 3, the controller 5 may open the acidic liquid valve 64 at thesame time as opening the alkaline chemical liquid valve 21 of theprocessing unit 2 or may open the acidic liquid valve 64 before or afteropening the alkaline chemical liquid valve 21. Similarly, controller 5may close the acidic liquid valve 64 at the same time as closing thealkaline chemical liquid valve 21 of the processing unit 2 or may closethe acidic liquid valve 64 before or after closing the alkaline chemicalliquid valve 21.

The exhaust generated at the processing unit 2 flows into the exhaustinflow chamber 33 after elapse of a time that is in accordance with apath length and a flow velocity of the exhaust in the path from theprocessing unit 2 to the exhaust inflow chamber 33. That is, there is atime difference between the generation of exhaust at the processing unit2 and the inflow of exhaust into the exhaust inflow chamber 33. Thecontroller 5 may thus delay the timing of opening the acidic liquidvalve 64 based on this time difference. Also, even when the supplying ofthe chemical liquid to the substrate W is stopped, there is residualexhaust containing the chemical liquid inside the processing unit 2 andtherefore the exhaust containing the chemical liquid flows into theexhaust inflow chamber 33 for a while after the supplying of thechemical liquid is stopped. The controller 5 may thus delay the timingof closing the acidic liquid valve 64 based on this time difference.

The sprayers 54 are constantly spraying water as the scrubbing liquidand therefore the acidic exhaust and the organic exhaust that flow intothe exhaust inflow chamber 33 are cleaned by contact with the water mistdrifting in the exhaust inflow chamber 33 and contact with the waterdroplets retained by the chemical liquid separator 36. Also, during theperiod in which the alkaline chemical liquid supplying step is beingperformed at the processing unit 2, the sprayers 54 spray dilutesulfuric acid as the scrubbing liquid and therefore the alkaline exhaustthat flows into the exhaust inflow chamber 33 is cleaned by theneutralization reaction of the pollutant inside the alkaline exhaust andthe dilute sulfuric acid. Therefore, even when any of the acidicexhaust, the alkaline exhaust, and the organic exhaust is expelled fromthe processing unit 2, the exhaust is cleaned to a harmless state by thescrubber 3 and then expelled from the scrubber 3.

As described above, with the present preferred embodiment, the exhaustthat is generated at the processing unit 2 and contains the chemicalliquid is guided toward the exterior of the substrate processingapparatus 1 by the exhaust passage 41 of the scrubber 3. The sprayers 54of the scrubber 3 can discharge each of a plurality of types ofscrubbing liquids individually inside the exhaust passage 41. Thescrubber 3 makes the sprayers 54 discharge the scrubbing liquid insidethe exhaust passage 41 to bring the exhaust, flowing through the exhaustpassage 41, in contact with the scrubbing liquid. The chemical liquidcomponent is thereby removed from the exhaust and the cleaned exhaust isexpelled to the exhaust equipment disposed outside the substrateprocessing apparatus 1.

Based on the type of chemical liquid contained in the exhaust, thecontroller 5 selects the type of scrubbing liquid discharged by thesprayers 54. Therefore, even if the type of pollutant contained in theexhaust changes during the processing of the substrate W or the type ofpollutant contained in the exhaust changes in accordance with thecontents of the process, the controller 5 can bring the scrubbingliquid, which is specialized to the chemical liquid component containedin the exhaust, in contact with the exhaust. The substrate processingapparatus 1 can thus clean, within its interior, the exhaust generatedat the processing unit 2 and decrease the residual amount of thechemical liquid component contained in the exhaust.

The exhaust generated at the processing unit 2 can thus be cleanedinside the substrate processing apparatus 1 and therefore an apparatusthat removes the pollutant, such as the chemical liquid component, etc.,from the exhaust does not need to be provided in the plant in which thesemiconductor processing apparatus 1 is installed. In other words, theexhaust that is removed of the chemical liquid component is expelledfrom the semiconductor processing apparatus 1 and, therefore a user ofthe semiconductor processing apparatus 1 needs only to prepare a generalapparatus for processing the exhaust and does not need to prepare adedicated apparatus that removes the chemical liquid component from theexhaust.

Also with the present preferred embodiment, the scrubber filter 46 thatallows passage of gas is disposed in the exhaust passage 41. When thesprayers 54 discharge the scrubbing liquid, the atmosphere that containsthe scrubbing liquid drifts inside the exhaust passage 41 and attachesto the scrubber filter 46. The scrubbing liquid is thus retained on anouter surface of the scrubber filter 46 and an inner surface of thescrubber filter 46. The exhaust flowing through the exhaust passage 41toward the exterior of the substrate processing apparatus 1 passesthrough voids in the interior of the scrubber filter 46.

In passing through the interior of the scrubber filter 46, the exhaustthat contains the pollutant contacts the scrubbing liquid dropletsretained in the scrubber filter 46. By the scrubbing liquid beingretained in the scrubber filter 46 in this process, the scrubbing liquidpresent inside exhaust passage 41 is increased in surface area so thatan area of contact between the exhaust and the scrubbing liquid is alsoincreased. A time of contact and the area of contact between the exhaustand the scrubbing liquid are thereby increased and the pollutant isremoved efficiently from the exhaust.

Also with the present preferred embodiment, the scrubbing liquid fromthe sprayers 54 is blown onto the scrubber filter 46. The scrubbingliquid discharged from the sprayers 54 thus hits the scrubber filter 46directly and the scrubbing liquid is supplied reliably to the scrubberfilter 46. The amount of scrubbing liquid retained by the scrubberfilter 46 is thus increased and the exhaust is reliably brought incontact with the scrubbing liquid retained by the scrubber filter 46.The residual amount of the pollutant contained in the exhaust is therebydecreased further and the cleanliness of the exhaust is improved.

Also with the present preferred embodiment, the mist filter 48 thatallows passage of gas and removes the liquid component from the gas isdisposed in the exhaust passage 41 at the position further downstreamthan the sprayers 54 and the scrubber filter 46 in the exhaustflow-through direction D1. The exhaust that is decreased in the residualamount of the pollutant by contact with the scrubbing liquid thus passesthrough the mist filter 48. The exhaust passing through the mist filter48 may contain the scrubbing liquid or other liquid component. Such aliquid component is captured by the mist filter 48 and is removed fromthe exhaust. Therefore, not only the pollutant but the liquid componentis also decreased in residual amount in the interior of the substrateprocessing apparatus 1.

Also with the present preferred embodiment, the suction force of thedrain apparatus 69 is transmitted to the drain port 73 that opens insidethe exhaust passage 41 and the liquid inside the exhaust passage 41 issuctioned into the drain port 73. The liquid inside the exhaust passage41 is thereby expelled. Although the drain port 73 is inside the exhaustpassage 41 and is thus in a state of low pressure, the liquid drainedfrom the drain port 73 is suppressed from flowing in reverse to theexhaust passage 41 by the suction force of the drain apparatus 72, andthe liquid inside the exhaust passage 41 can thus be drained reliably.

Also with the present preferred embodiment, the scrubber filter 46 isdisposed further upstream than the drain port 73. The drain apparatus 69has the drain passage 71 passing through the space between the scrubberfilter 46 and the bottom surface of the exhaust passage 41 and extendingfrom further upstream than the scrubber filter 46 to the drain port 73.A liquid present further upstream than the scrubber filter 46 is guidedtoward the drain port 73 by the drain passage 71. The drain apparatus 69can thus collect liquid from a wider range of the interior of theexhaust passage 41 and the residual amount of the liquid inside theexhaust passage 41 can thereby be decreased.

Also with the present preferred embodiment, the scrubbing liquid isdischarged constantly from the sprayers 54. That is, all of the sprayers54 continue to discharge the scrubbing liquid while the substrateprocessing apparatus 1 is in operation. The state in which the scrubbingliquid is retained by the scrubber filter 46 is thus maintainedreliably. The exhaust flowing through the exhaust passage 41 is thusreliably brought into contact with the scrubbing liquid retained by thescrubber filter 46. The residual amount of the pollutant contained inthe exhaust can thereby be decreased. Further, when the scrubber filter46 dries, a resistance that the scrubber filter 46 applies to a gas flowdecreases, and therefore by maintaining the scrubber filter 46 in a wetstate, fluctuation of exhaust pressure can be decreased. The exhaustpressure transmitted from the exhaust equipment to the processing unit 2via the scrubber 3 can thereby be stabilized.

When the exhaust pressure transmitted to the processing unit 2fluctuates, disturbance of gas flow may occur inside the chamber 6. Bystabilizing the exhaust pressure transmitted to the processing unit 2,the gas flow inside the chamber 6 can be stabilized. Attachment offoreign matter, such as particles, etc., and attachment of a mist of theprocessing liquid to the substrate W inside the chamber 6 can thus besuppressed or prevented. The cleanliness of the substrate W can thus beimproved. Further, when the respective sprayers 54 discharge thescrubbing liquid constantly, the exhaust pressures transmitted to therespective processing units 2 are made uniform to enable variation ofprocessing quality of the substrate W among the plurality of processingunits 2 to be decreased.

Also with the present preferred embodiment, the gas-liquid separator 26that is disposed further upstream than the scrubber 3 separates liquidfrom the exhaust generated at the processing unit 2 and removes theliquid component from the exhaust. The exhaust that has been decreasedin liquid content by the gas-liquid separator 26 is delivered to thescrubber 3. The amount of the chemical liquid component to be removed atthe scrubber 3 can thus be decreased and consequently, the cleanlinessof the exhaust expelled from the substrate processing apparatus 1 can beimproved further.

Also with the present preferred embodiment, the plurality of individualpassages 42 of the exhaust passage 41 are connected respectively to theplurality of processing units 2 and the collection passage 43 of theexhaust passage 41 is connected to each of the plurality of individualpassages 42. The exhausts generated at the plurality of processing units2 are expelled from the plurality of processing units 2 into theplurality of individual passages 42 respectively. The exhausts thatflowed into the plurality of individual passages 42 are guided via thecollection passage 43 toward the exhaust equipment disposed outside thesubstrate processing apparatus 1. The exhaust generated at eachprocessing unit 2 is cleaned by contact with the scrubbing liquid in theprocess of flowing through the exhaust passage 41. The exhaustsgenerated at the plurality of processing units 2 can thus be cleanedinside the substrate processing apparatus 1 by the scrubber 3. There isthus no need to provide a plurality of scrubbers 3 in the substrateprocessing apparatus 1 in correspondence to the individual processingunits 2.

Also with the present preferred embodiment, the plurality of sprayers 54are disposed respectively in the plurality of individual passages 42.The scrubber 3 can thus make a scrubbing liquid, of a different typefrom the scrubbing liquid discharged in a certain individual passage 42,be discharged in another individual passage 42. The scrubber 3 can thusbring the exhaust in each individual passage 42 in contact with thescrubbing liquid specialized to the pollutant contained in the exhaust.Therefore even in a case where different processes are preformedrespectively in the plurality of processing units 2, the scrubber 3 canperform removal of the respectively corresponding chemical liquidcomponents.

Also with the present preferred embodiment, the plurality of scrubberfilters 46 are disposed respectively in the plurality of individualpassages 42. The scrubber 3 can thus bring the exhaust and the scrubbingliquid in contact reliably in each individual passage 42 and canincrease the area of contact between the exhaust and the scrubbingliquid inside each individual passage 42. The scrubber 3 can thusefficiently remove the pollutants from the exhausts generated at theplurality of processing units 2 and further improve the cleanliness ofthe exhausts.

Also with the present preferred embodiment, the plurality of mistfilters 48 are disposed respectively in the plurality of individualpassages 42. That is, a dedicated mist filter 48 is provided accordingto each individual passage 42. The scrubber 3 can thus remove the liquidcomponent from the exhaust in each individual passage 42. The scrubber 3can thus reliably remove the liquid component from the exhaustsgenerated at the plurality of processing units 2 and further improve thecleanliness of the exhausts.

Also with the present preferred embodiment, the plurality of drainpassages 71 of the drain apparatus 69 respectively correspond to theplurality of individual passages 42 and each drain passage 71 extendsfrom the corresponding individual passage 42 to the collection passage43. The respective drain passages 71 are inclined with respect to thehorizontal plane and the downstream ends of the drain passages 71 aredisposed lower than the upstream ends of the drain passages 71 so thatthe liquids inside the plurality of individual passages 42 flow throughthe plurality of drain passages 71 to the collection passage 43 bygravity. The liquids inside the plurality of individual passages 42 arethus collected into the collection passage 43. The drain apparatus 69suctions the liquid inside the collection passage 43 from the drain port73 that opens in the collection passage 43. The drain apparatus 69 canthus collect liquid from a wider range of the interior of the exhaustpassage 41 and the residual amount of the liquid inside the exhaustpassage 41 can thereby be decreased.

Although the preferred embodiment of the present invention has beendescribed above, the present invention is not restricted to the contentsof the above-described preferred embodiment and various modificationsare possible within the scope of the claims.

For example, although with the above-described preferred embodiment, thecase where the sprayers 54 are disposed in each individual passage 42was described, the sprayers 54 may instead be disposed in the collectionpassage 43 as shown in FIG. 7. In this case, not only the sprayers 54but the scrubber filter 46 and the mist filter 48 may also be disposedin the collection passage 43 as shown in FIG. 7.

In the case where the sprayers 54 are disposed in the collection passage43, the sprayers 54 do not have to be provided in each of the individualpassages 42. The substrate processing apparatus 1 can thus be reduced inthe number of parts and the substrate processing apparatus 1 can besimplified in structure. Similarly, in the case where the scrubberfilter 46 and the mist filter 48 are disposed in the collection passage43, the scrubber filter 46 and the mist filter 48 do not have to beprovided in each of the individual passages 42. The substrate processingapparatus 1 can thus be reduced in the number of parts and the substrateprocessing apparatus 1 can be simplified in structure.

Also, although with the preferred embodiment, the case where thesprayers 54 discharge the scrubbing liquid constantly was described, thesprayers 54 may discharge the scrubbing liquid intermittently asindicated by alternate long and two short dashes lines in FIG. 6. By thescrubbing liquid thus being discharged intermittently from the sprayers54, a consumption amount of the scrubbing liquid can be decreased.

In the case where the sprayers 54 discharge the scrubbing liquidintermittently, an interval (time from stoppage to restart of discharge)at which the sprayers 54 discharge the scrubbing liquid may be a fixedinterval determined in advance or a certain interval set based on a gaspressure in the exhaust passage 41.

Specifically, the controller 5 may make the sprayers 54 discharge thescrubbing liquid intermittently based on the detection value or valuesof either or both of the upstream exhaust pressure sensors 78 and thedownstream exhaust pressure sensor 79. When the scrubber filter 46dries, the exhaust resistance of the scrubber filter 46 decreases andtherefore the gas pressure in the upstream exhaust duct 32 decreases(the absolute value of negative pressure increases) and the gas pressureinside the exhaust collection chamber 34 increases (the absolute valueof negative pressure decreases). The controller 5 can thus maintain thestate in which the scrubber filter 46 is wetted sufficiently whiledecreasing the consumption amount of the scrubbing liquid by making thesprayers 54 discharge the scrubbing liquid intermittently based on thedetection value or values of either or both of the upstream exhaustpressure sensors 78 and the downstream exhaust pressure sensor 79.

Further, the suction force of the exhaust equipment is transmitted toeach processing unit 2 via the scrubber filter 46 and therefore thecontroller 5 can adjust the exhaust pressure transmitted to theprocessing unit 2 by controlling the supplying of scrubbing liquid tothe scrubber filter 46. Therefore by controlling the supplying ofscrubbing liquid to the respective scrubber filters 46 based on thedetection value or values of either or both of the upstream exhaustpressure sensors 78 and the downstream exhaust pressure sensor 79, thecontroller 5 can decrease exhaust pressure differences among theplurality of processing units 2. The controller 5 can thus make uniformthe exhaust pressures inside the respective processing units 2.

Also, although with the preferred embodiment, the case where theplurality of scrubber filters 46 are disposed respectively in theplurality of individual passages 42 was described, the scrubber 3 mayinstead include a plurality of scrubber filters 46 corresponding to anindividual passage 42 in common and a filter switching apparatus 80 thatswitches the state of each of the plurality of scrubber filters 46individually.

Specifically, as shown in FIG. 8 and FIG. 9, the plurality of scrubberfilters 46 provided according to the respective types of chemicalliquids (for example, a scrubber filter 46 for the acidic chemicalliquid and a scrubber filter 46 for the alkaline chemical liquid) andthe filter switching apparatus 80 that switches the state of each of theplurality of scrubber filters 46 individually may be associated with asingle individual passage 42. Similarly, although the case where thesingle scrubber filter 46 is disposed in the collection passage 43 wasdescribed with FIG. 7, the plurality of scrubber filters 46 and thefilter switching apparatus 80 may be associated with the collectionpassage 43.

Each of scrubber filters 46A of cubical shapes shown in FIG. 8 isswitched between a removal state in which the gas inside exhaust passage41 passes through the scrubber filter 46A and a removal stop state inwhich the passage of the gas through the scrubber filter 46A is stopped.The removal state is a state in which the scrubber filter 46A isdisposed at a removal position (position of the scrubber filter 46A atthe left side) inside the exhaust passage 41 and the removal stop stateis a state in which the scrubber filter 46A is disposed at a removalstop position (position of the scrubber filter 46A at the right side)outside the exhaust passage 41. The filter switching apparatus 80 canthus switch the scrubber filter 46A that removes the pollutant from theexhaust by moving the scrubber filters 46A between the removal positionand the removal stop position.

Also, each of scrubber filters 46B of circular columnar shapes shown inFIG. 9 is disposed in the exhaust passage 41 in an attitude where acenter line of the scrubber filter 46B is orthogonal to the exhaustflow-through direction D1. The plurality of scrubber filters 46B arealigned in a direction orthogonal to the exhaust flow-through directionD1 and an axial direction of each scrubber filter 46B. Each scrubberfilter 46B is housed inside a filter case 47B of circular cylindricalshape having an outer peripheral portion provided with two openingportions 47 b that face each other in a diameter direction. The filterswitching apparatus 80 rotates the filter case 47B around its centerline between a removal position at which the two opening portions 47 bare open (position of the scrubber filter 46B at the upper side) and aremoval stop position at which the two opening portions 47 b are closedby a shielding member 81 disposed inside the exhaust passage 41(position of the scrubber filter 46B at the lower side).

As shown in FIG. 9, when the filter case 47B is disposed at the removalposition (position of the scrubber filter 46B at the upper side), thescrubber filter 46B is switched to a removal state in which the gasinside exhaust passage 41 passes through the scrubber filter 46B. Whenthe filter case 47B is disposed at the removal stop position (positionof the scrubber filter 46B at the lower side), the scrubber filter 46Bis switched to a removal stop state in which the passage of the gasthrough the scrubber filter 46B is stopped. The filter switchingapparatus 80 can thus switch the scrubber filter 46B that removes thepollutant from the exhaust by rotating the filter cases 47B.

Also, although with the preferred embodiment, the case where thescrubber filter 46 and the mist filter 48 are disposed in each of allindividual passages 42 was described, the scrubber filter 46 and themist filter 48 may be disposed in just a portion of the individualpassages 42. Also, at least one of either of the scrubber filter 46 andthe mist filter 48 may be omitted from all of the individual passages42. Similarly, although with FIG. 7, the case where the scrubber filter46 and the mist filter 48 are disposed in the collection passage 43 wasdescribed, at least one of either of the scrubber filter 46 and the mistfilter 48 may be omitted from the collection passage 43. In this case,the chemical liquid component contained in the exhaust is removed onlyby the scrubbing liquid discharged from the sprayers 54. Although thearea of contact between the scrubbing liquid and the chemical liquidcomponent is decreased, the structure can be simplified.

Also, although with the preferred embodiment, the case where the liquidinside the exhaust passage 41 is expelled from one location (the drainport 73) was described, the liquid inside the exhaust passage 41 mayinstead be expelled from a plurality of drain ports 73. For example, aplurality of drain ports 73 corresponding respectively to the pluralityof sprayers 54 may be provided inside the exhaust passage 41. In thiscase, the gap between the lower surface of the chemical liquid separator36 and the bottom surface of the exhaust cleaning box 38 does not haveto be provided and the chemical liquid separator 36 may be in contactwith the bottom surface of the exhaust cleaning box 38. That is, thechemical liquid separator 36 may partition the exhaust passage 41 intoan upstream side and a downstream side completely. The same applies tothe mist separator 37.

Also, although with the preferred embodiment, the case where the liquidinside the exhaust passage 41 is expelled into the drain piping 70 incommon was described, the drain piping 70 may be switched in accordancewith the type of scrubbing liquid discharged from the sprayers 54.Specifically, a plurality of drain pipings 70 and a plurality of drainvalves 77 may be provided. In this case, the controller 5 can switch thedrain piping 70 in accordance with the type of scrubbing liquiddischarged from the sprayers 54 by switching the plurality of drainvalves 77.

Also, although with the preferred embodiment, the case where thesprayers 54 discharge each of two types of scrubbing liquids (the acidicscrubbing liquid and the neutral scrubbing liquid) individually wasdescribed, the sprayers 54 may instead discharge each of three types ofscrubbing liquids (an acidic scrubbing liquid, an alkaline scrubbingliquid, and a neutral scrubbing liquid) individually or may dischargeeach of two types of scrubbing liquids, besides a combination of theacidic scrubbing liquid and the neutral scrubbing liquid, individually.Also, in a case where each of an acidic scrubbing liquid and an alkalinescrubbing liquid is discharged individually from a sprayer 54 in common,the controller 5 may make a neutral scrubbing liquid be discharged fromthe sprayer 54 before switching the scrubbing liquid from one to theother of the acidic scrubbing liquid and the alkaline scrubbing liquid.In this case, the controller 5 can rinse the interior of the sprayer 54and the interior of the piping with the neutral scrubbing liquid andmixing of the acidic scrubbing liquid and the alkaline scrubbing liquidcan thus be prevented.

Also, although with the preferred embodiment, the case where eachsprayer 54 includes the plurality of spray nozzles 57 and the pluralityof types of scrubbing liquids (the acidic scrubbing liquid and theneutral scrubbing liquid) are discharged from the spray nozzles 57 incommon was described, the plurality of types of scrubbing liquids mayinstead be discharged from separate spray nozzles 57. For example, adedicated spray nozzle 57 may be provided for each type of scrubbingliquid.

Also, although with the preferred embodiment, the case where twoprocessing units 2 are provided in the substrate processing apparatus 1was described, the number of processing units 2 may be one or may be notless than three.

Also, although with the preferred embodiment, the case where eachprocessing unit 2 is a single substrate processing type unit thatprocesses the substrate W one by one was described, the processing unit2 may be a batch type unit that processes a plurality of substrates W ina batch. That is, the substrate processing apparatus 1 may be a batchtype apparatus.

Also, although with the preferred embodiment, the case where thesubstrate processing apparatus 1 is an apparatus that processes thedisk-shaped substrate W was described, the substrate processingapparatus 1 may instead be an apparatus that processes a polygonalsubstrate W, such as a substrate for liquid crystal display device, etc.

While a preferred embodiment of the present invention has been describedin detail above, this is merely a specific example used to clarify thetechnical contents of the present invention, and the present inventionshould not be interpreted as being limited only to this specificexample, and the spirit and scope of the present invention shall belimited only by the appended claims.

The present application corresponds to Japanese Patent Application No.2013-44540 filed on Mar. 6, 2013 in the Japan Patent Office, and theentire disclosure of this application is incorporated herein byreference.

DESCRIPTION OF THE SYMBOLS

-   1: Substrate processing apparatus-   2: Processing unit-   3: Scrubber-   5: Controller-   26: Gas-liquid separator-   27: Gas-liquid separation box-   28: Liquid piping-   29: Gas piping-   32: Upstream exhaust duct-   33: Exhaust inflow chamber-   34: Exhaust collection chamber-   35: Downstream exhaust duct-   36: Chemical liquid separator-   37: Mist separator-   38: Exhaust cleaning box-   41: Exhaust passage-   42: Individual passage-   43: Collection passage-   44: Gas inlet-   45: Exhaust outlet-   46: Scrubber filter-   46A: Scrubber filter-   46B: Scrubber filter-   47: Filter case-   47B: Filter case-   48: Mist filter-   49: Mist filter case-   50: Upstream opening-   51: Downstream opening-   52: Lower opening-   53: Spraying apparatus-   54: Sprayer (discharger)-   55: Scrubbing liquid supplying apparatus-   56: Spray column-   57: Spray nozzle-   69: Drain apparatus-   70: Drain piping-   71: Drain passage-   72: Suction apparatus-   73: Drain port-   74: Aspirator-   78: Upstream exhaust pressure sensor-   79: Downstream exhaust pressure sensor-   80: Filter switching apparatus-   81: Shielding member-   D1: Flow-through direction-   W: Substrate

1. A substrate processing apparatus comprising: a processing unit thatsupplies at least one of a plurality of types of chemical liquids to asubstrate; a scrubber including an exhaust passage that guides exhaust,generated at the processing unit and containing the chemical liquid,toward an exhaust equipment disposed outside the substrate processingapparatus and a discharger that discharges each of a plurality of typesof scrubbing liquids, that clean the exhaust, individually inside theexhaust passage, the scrubber being configured to clear the exhaust bybringing the exhaust flowing through the exhaust passage in contact withthe scrubbing liquid; and a controller that selects any one of theplurality of types of scrubbing liquids based on the type of chemicalliquid contained in the exhaust and makes the selected scrubbing liquidbe discharged from the discharger.
 2. The substrate processing apparatusaccording to claim 1, wherein the scrubber further includes a scrubberfilter that is disposed in the exhaust passage, allows gas flowingthrough the exhaust passage to pass through the scrubber filter, andretains liquid internally.
 3. The substrate processing apparatusaccording to claim 2, wherein the discharger discharges the scrubbingliquid toward the scrubber filter.
 4. The substrate processing apparatusaccording to claim 2, wherein the scrubber further includes a mistfilter that is disposed in the exhaust passage at a position furtherdownstream than the discharger and the scrubber filter, allows gasflowing through the exhaust passage to pass through the mist filter, andremoves a liquid component from the gas.
 5. The substrate processingapparatus according to claim 1, wherein the scrubber further includes adrain apparatus that expels liquid inside the exhaust passage by makingthe liquid be suctioned into a drain port that opens inside the exhaustpassage.
 6. The substrate processing apparatus according to claim 5,wherein the scrubber further includes a scrubber filter that is disposedin the exhaust passage at a position further upstream than the drainport, allows gas flowing through the exhaust passage to pass through thescrubber filter, and retains liquid internally, and the drain apparatusincludes a drain passage that extends from a position upstream than thescrubber filter to the drain port through a position below the scrubberfilter such that the liquid inside the exhaust passage flows toward thedrain port along the drain passage.
 7. The substrate processingapparatus according to claim 1, wherein the scrubber further includes ascrubber filter that is disposed in the exhaust passage, allows gasflowing through the exhaust passage to pass through the scrubber filter,and retains liquid internally, and the discharger discharges thescrubbing liquid constantly.
 8. The substrate processing apparatusaccording to claim 1, wherein the scrubber further includes a scrubberfilter that is disposed in the exhaust passage, allows gas flowingthrough the exhaust passage to pass through the scrubber filter, andretains liquid internally, and the discharger discharges the scrubbingliquid intermittently.
 9. The substrate processing apparatus accordingto claim 8, wherein the scrubber further includes an exhaust pressuresensor that detects a gas pressure in the exhaust passage and thecontroller makes the discharger discharge the scrubbing liquidintermittently based on a detection value of the exhaust pressuresensor.
 10. The substrate processing apparatus according to claim 1,wherein the scrubber further includes a plurality of scrubber filtersthat allow gas flowing through the exhaust passage to pass through theplurality of scrubber filters and retain liquid internally and a filterswitching apparatus switching a state of each of the plurality ofscrubber filters individually, the filter switching apparatus switchesthe state of each of the plurality of scrubber filters individuallybetween a removal state in which the gas inside exhaust passage passesthrough the scrubber filter and a removal stop state in which thepassage of the gas through the scrubber filter is stopped, and thecontroller selects any one of the plurality of scrubber filters based onthe type of chemical liquid contained in the exhaust and causes thefilter switching apparatus to switch the states of the plurality ofscrubber filters such that the exhaust passes through the selectedscrubber filter.
 11. The substrate processing apparatus according toclaim 1, wherein the processing unit includes a gas-liquid separatorthat is disposed further upstream than the scrubber and removes liquidfrom the exhaust generated at the processing unit.
 12. The substrateprocessing apparatus according to claim 1, wherein the processing unitincludes a plurality of processing units, each of which supplies atleast one of a plurality of types of chemical liquids, and the exhaustpassage includes a plurality of individual passages connectedrespectively to the plurality of processing units and a collectionpassage extending downstream from the plurality of individual passages.13. The substrate processing apparatus according to claim 12, whereinthe discharger includes a plurality of dischargers disposed respectivelyin the plurality of individual passages.
 14. The substrate processingapparatus according to claim 13, wherein the scrubber further includes aplurality of scrubber filters that are disposed respectively in theplurality of individual passages, allow gas flowing through the exhaustpassage to pass through the plurality of scrubber filters, and retainliquid internally.
 15. The substrate processing apparatus according toclaim 14, wherein the scrubber further includes a plurality of mistfilters that are disposed respectively in the plurality of individualpassages at positions further downstream than the plurality ofdischargers and the plurality of scrubber filters, allow gas flowingthrough the exhaust passage to pass through the plurality of mistfilters, and remove a liquid component from the gas.
 16. The substrateprocessing apparatus according to claim 12, wherein the discharger isdisposed in the collection passage.
 17. The substrate processingapparatus according to claim 16, wherein the scrubber further includes ascrubber filter that is disposed in the collection passage, allows gasflowing through the exhaust passage to pass through the scrubber filter,and retains liquid internally.
 18. The substrate processing apparatusaccording to claim 17, wherein the scrubber further includes a mistfilter that is disposed in the collection passage at a position furtherdownstream than the discharger and the scrubber filter, allows gasflowing through the exhaust passage to pass through the mist filter, andremoves a liquid component from the gas.
 19. The substrate processingapparatus according to claim 12, wherein the scrubber further includes adrain apparatus that expels a liquid inside the exhaust passage bymaking the liquid be suctioned into a drain port that opens inside thecollection passage, and the drain apparatus includes a plurality ofdrain passages extending from the plurality of individual passages tothe collection passage and inclined with respect to a horizontal planesuch that the liquid inside the exhaust passage flows from the pluralityof individual passages to the collection passage.